Short to Medium -Term Performance of Rice-Wheat System without Tillage and Direct Seeding.

Modern rice-wheat production system (RWS) of South Asia is tillage, labor, water and energy intensive.  It has led to production fatigue, high input uses and degradation of resource base. Our research program in South Asia has made significant effort in developing alternative resource efficient tillage and crop establishment practices following the framework of integrated crop and resource management. This paper reports on-station trial performance of rice, wheat and key soil quality parameters after continuous 7 year no-till cropping conducted in Northwestern India. 

The pooled (7 years) analysis of yield data revealed that the system productivity (rice+wheat) under double no-till (11.85 Mg ha^-1) and traditional-till practice (12.67 Mg ha^-1) were comparable. Double no-till system produced higher wheat yield (5.2 Mg ha^-1) than traditional practice (4.6 Mg ha^-1) whereas rice yield was marginally lower. After seven years, soil quality was significantly improved. Steady state infiltration rate was higher in double no-till system (0.41 cm hr^-1) compared to traditional practice (0.11 cm hr^-1). The surface density of soils (0-5 and 6-10 cm depth) was similar under both systems whereas higher sub-surface soil density (15-20 cm) was observed under traditional system (1.74 Mg M^-3). The cone penetration resistance (CPR) remain unchanged at surface but reduced at sub-surface soil after continuous no tillage. On the other hand in conventionally-tilled plots, the sub-surface was compacted. The aggregate stability index was higher under double no-till system (2.9 MWD mm) with maximum of > 0.25 mm soil aggregates (74.1%) compared to traditional-till (1.3 & 49.4, respectively). The study also observed that double no-till system regulates soil surface temperature and facilitates better soil biological activities.   Results indicate that the no-till practice is an efficient alternative to energy intensive tillage for improving the soil quality and sustainability of RWS.